\documentclass[UTF8, zihao = -4, a4paper, oneside]{ctexart}

\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{geometry}
\geometry{
    ignoreall, nomarginpar, %页眉页脚边注不算在total body中；关闭边注
    left = 2.5cm, right = 2.5cm, top = 2.5cm, bottom = 2.5cm,
    headsep = 1cm, footskip = 1cm
}

\title{\heiti 高等数学笔记}
\author{Nathaniel}

\begin{document}
    \maketitle

    % 积化和差
    \input{data/JiHuaHeCha.tex}
    % 和差化积
    \input{data/HeChaHuaJi.tex}

    % 正割函数和余割函数
    正割函数：$\sec x = \dfrac{1}{\cos x}$ \qquad
    余割函数：$\csc x = \dfrac{1}{\sin x}$

    % 极限运算法则
    \input{data/JiXianYunSuanFaZe.tex}
\end{document}